I downloaded and installed ISE 11.3 update which brings an unknown bundle of updates to ISE. Unknown because they still haven't updated the ARs (Answer Records) to detail the changes / fixes / issues. I can say for sure that they haven't fixed the external editor issue (http://ionipti.blogspot.com/2009/05/xilinx-ise-using-external-editor-not.html). I see that they do have updates for many of their IP cores.
Seems to me that the major updates are related to Virtex 6 and Spartan 6 support. It would be nice to see the release notes whenever Xilinx makes them available.
Struggling now with ISIM issues on Vista x64.... (http://forums.xilinx.com/xlnx/board/message?message.uid=46879)